High pressure valve and method

ABSTRACT

A high pressure valve employing a nonrotating needle. The valve actuating stem is threadedly received in a liner sleeve of the valve packing nut. The inner end of the actuating stem is bifurcated and includes a transverse cylindrical bore intersected by an axially directed slot somewhat smaller in breadth than the diameter of the bore and extending to the inner end of the stem. A valve needle including an enlarged spherical outer end is adapted to be received in the bore and slot. Essentially line contact is provided between the bearing surfaces of the valve needle and of the actuating stem. Sealing and support for the valve needle are provided by the combination of a seal washer, sealing member and alignment bushing disposed in a counterbore of the valve body.

United States Patent Bedo et al. 51 July 25, 1972 541 HIGH PRESSURE VALVE AND 2,344,747 3/1944 Sperry et al ..251/168 x METHOD 394,167 12/1888 Gold ..25l/86 X 1,523,953 1/1925 Giesler ...25l/26$ 1 1 lnvemom AM No, Walton "Ills; q Beck, 2,613,055 10/1952 Slapnicher ..251/264 Ckveland Heights, both Ohw 3,278,156 10/1966 Callahan et a1. .....2s1/s4 x [731 Assign: FOREIGN PATENTS OR APPLICATIONS [221 1969 1,203,049 7/1959 France .251/83 21 1 862, 04 566,958 1/1945 Great Britain ..25l/88 Primary Examiner-Henry T. Klinksiek [52] U.S. Cl ..25 l/88, 251/122, 251/214, Attorney pay, Sharpe and Mulhonand 251/264, 287/91 [51] Int. Cl ..Fl6lt 2 5/00 57 ABSTRACT [58] Field of Search ..2s7/90, 90 B, 91; 251/83, 86, I

251/88, 168, 84, 264, 265, 87, 357; 59/95 A high pressure valve employmg a nonrotatmg needle. The valve actuatrng stem 1s threadedly rece1ved m a lmer sleeve of I 56] Reknnm Cited the valve packing nut. The inner end of the actuating stem is bifurcated and 1nc1udes a transverse cyllndncal bore Inter- UNITED STATES PATENTS sected by an axially directed slot somewhat smaller in breadth than the diameter of the bore and extending to the inner end 778,82] l2/l904 Bury ea ..287/90 of the Stem. A valve needle including an enlarged spherical 4/1923 cmzlerw' outer end is adapted to be received in the bore and slot. Essen- 11898519 2/1933 "251/88 tialiy line contact is provided between the bearing surfaces of 4/1935 251/86 X the valve needle and of the actuating stem. Sealing and sup- 2'853'l0l 9/1958 w'lhams 251/86 X port for the valve needle are provided by the combination of a 2,963,038 l2/1960 sharp 251/88 x seal washer, sealing member and alignment bushing disposed 3,049,332 8/1962 Webster ..25 1/88 in a counterbore fth l body 3,305,207 2/1967 Calderoni et al. .251/88 3,292,895 12/ 1 966 Leger et a1 ..251/83 7 Claims, 8 Drawing Figures I52 |Q2 I00 [6 22 l I 1o 94 l 44 42 2% \BG 42 44 54 e0 #2 34 e 74 36 23 T Bi 5 46 I46 e. 54 26 9 21 915 38 24 38 4o PATENFHms ms 70 Ml l46l54 i illllllll SHEEI 2 BF 2 ATTOR N E YS.

HIGH PRESSURE VALVE AND METHOD A method of assembly of a nonrotating needle type valve including the steps of providing a valve body, providing a needle having an enlarged spherical outer end, providing a valve actuating stem having a bifurcated inner end defined by a transverse cylindrical bore intersected by an axially directed slot somewhat smaller in breadth than the diameter of the bore and extending to the inner end of the stem, positioning the needle and stem in a side-by-side relationship, laterally moving the needle with respect to the stern such that the enlarged spherical outer end is received in the bore thus capturing the needle in the bifurcated end of the stem and attaching the stem in the valve body.

BACKGROUND OF THE INVENTION This invention relates to a high pressure valve and more particularly to a high pressure valve of the nonrotating needle type.

This invention further relates to a method of assembly of a nonrotating needle type valve.

Needle valves are particularly useful in industry for regulating the flow of fluids under pressure, especially in the operation of sensitive instruments. This type of valve employs a slender needle which is adapted to be brought into and out of contact with a valve seat. The valve seat itself is located between inlet and outlet passageways in the valve body. The needle therefore acts as a means either for controlling the flow rate of fluid through the valve body, or for interrupting the flow altogether. Thus, depending upon the design of the needle, flow of fluid through the body may be either metered or controlled, or shut-off entirely.

The basic design of prior art needle valves employs a valve actuating stem threadedly received within the packing nut of the valve or within the valve body directly. The needle is adapted to be carried by the actuating stem such that rotation of the valve handle will bring the needle tip into and out of engagement with the valve seat. Depending upon the particular connecting means between the needle and the valve stem, the needle may be either of the rotating or nonrotating type.

if the needle is rigidly connected to the valve stem, the needle tip will rotate with rotation of the stem.

Alternately, if a lost motion connection is provided between the needle and the stem, rotation of the stern will not impart rotation to the needle. In the nonrotating needle type of valve structure, rotary motion of the valve stem is transformed into linear motion of the needle thus moving the nonrotating needle tip into and out of engagement with the valve seat.

The nonrotating needle has obvious advantages over the rotating needle. In the rotating needle structure, severe scoring of the valve seat may take place as the needle tip is brought into engagement with the seat. This scoring occurs as the needle tip is wiped across the valve seat in closing of the valve, and severely affects the reliability of the seal at the valve seat. Such scoring is all but eliminated when the valve needle is rendered nonrotating with respect to the valve seat and is brought into and out of engagement with the valve seat by a direct linear motion.

Several difficulties in prior art valves of the non-rotating needle type have been encountered in industry, one of the more common difi'rculties being that the needle itself is not readily removable in the event that it is damaged. It is not uncommon in prior art needle valves to find that the actuating stem and needle combination must be replaced in the event of damage to the needle since the needle is captured upon the actuating stem by upsetting a portion of the stem end about the needle. Replacement of the needle itself is thus virtually impossible in view of the difficulty of removing the damaged needle without significant damage to the stem.

Another problem of prior art needle valve designs is that the needle is not always rendered nonrotating with respect to the stem. In certain prior art designs frictional effects may produce a slight amount of rotation of the needle with rotation of the stem resulting in undesirable scoring of the valve seat.

Such frictional effects are inherent in the types of connections provided between the needle and the stem of certain prior art needle valves.

An additional problem of prior art needle valves is the pressure limitation of such valves. Where alignment of the needle with respect to the axis of the valve seat is not accurately maintained, a definite pressure limitation is placed on the valve depending upon the degree of misalignment of the needle, the degree of wear in the valve seat and other factors. Consequently, many prior art needle valve designs are not suitable for high pressure application because of needle misalignment.

Also related to pressure limitations in prior art needle valves are the limitations imposed by sealing about the needle. In many prior art designs, the sealing structure about the needle body is ineffective for high pressure application.

BRIEF SUMMARY OF THE INVENTION Briefly summarized, this invention relates to a high pressure valve of the nonrotating needle type and also to a method of assembly of a nonrotating needle valve.

In the preferred embodiment of the apparatus of this inven tion, the valve stem is threadedly received within a liner sleeve of the packing nut. Acme threads are provided on the actuating stem which mate with comparable threads on the packing nut liner sleeve. The inner end of the actuating stem is bifurcated, being defined by a transverse cylindrical bore intersected by an axially directed slot of somewhat smaller breadth than the diameter of the bore and extending from the bore to the inner end of the stem.

A valve needle is carried by the bifurcated end of the stem. The valve needle includes an enlarged spherical outer end adapted to be received in the cylindrical bore of the stem in essentially line contact relationship. The inner end of the needle is provided with a tip adapted to cooperate with the valve seat to provide either a metering, control or shut-off function.

Disposed about the body of the needle are a seal washer and an alignment bushing positioned one on either side of a sealing member. The packing nut is threadedly received in the valve body and at its inner end is adapted to engage the alignment bushing to apply a compressive force to the sealing member which in turn sealingly engages both the valve body and the needle. The alignment bushing, sealing member and seal washer together cooperate to align the needle with respect to the axis of the valve seat.

An inlet and outlet passageway in the valve body respectively lead to and from the valve seat. Suitable tube, or other, connections are provided at the valve body so that the valve may be connected into a flow line.

The method of this invention includes the steps of providing a valve body including a valve seat disposed between inlet and outlet passageways, providing a needle having an enlarged spherical surface at the outer end thereof and a tip at the inner end thereof adapted to cooperate with the valve seat, providing a valve actuating stem having a bifurcated inner end defined by a transverse cylindrical bore intersected by a slot somewhat smaller in breadth than the diameter of the bore and extending to the inner end of the stem, positioning the needle and stem in a side-by-side relationship, and laterally moving the needle with respect to the stern such that the enlarged spherical end of the needle is received in the bore of the stem thus capturing the needle in the bifurcated end of the stem, and attaching the valve stem in the valve body.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete description of the apparatus and method of this invention will be had with reference to the accompanying drawings in which:

FIG. 1 is an elevational cross-sectional view of a valve embodying the principles of this invention;

FIG. 2 is a fragmentary plan elevational view, partially in section, taken along the line 2-2 of FIG. I;

FIG. 3 is an exploded view, in partial section, of a valve actuating stem and packing nut embodying the principles of this invention;

FIG..4 is a sectional view taken along the line 44 of FIG. 3 and including in addition in phantom outline the respective positions of the needle as it is inserted into the bifurcated end of the stem;

FIG. 5 is a sectional view taken along the line 5-5 of FIG.

FIG. 6 is an elevational view of an illustrative alternate embodiment of the needle;

FIG. 7 is an elevational view of a further illustrative alternate embodiment of the needle; and

FIG. 8 is an elevational view of a still further illustrative alternate embodiment of the needle.

DESCRIPTION OF THE VALVE Turning now to FIG. 1, the preferred embodiment of the apparatus of this invention will now be described in detail.

In FIG. I, there is shown a valve 10 secured to support 12 by means of cap screws l4, l6. Cap screws l4, 16 extend through support 12 and into tapped holes 18 of valve body 20. Captured between the heads of cap screws 14, 16 and support 12 is a keeper 22 whose function will be described in greater detail as the description proceeds.

Valve body is provided with inlet and outlet passageways 24, 26. respectively, which intersect bore 28. A valve seat 30 is defined at the intersection of inlet passage 24 and bore 28.

Tube couplings or other suitable connections are provided at 32 for the respective inlet and outlet passageways 24, 26 in order that tubes or other flow lines 34 may be secured to the valve body.

TUBE COUPLINGS Briefly describing the tube couplings 32 of FIG. 1, it will be seen that each tube 34 is provided with a conical end 36 which engages a generally frusto-conical sealing surface 38 defined by the valve body 20. A bore 40 extends through each tube 34 and is in communication with a respective passageway 24, 26. The external surface of each tube is gripped by a pair of ferrules 42, 44. Front ferrule 42 is defined by a generally frustoconical nose portion 46 which engages camming mouth 48 defined by the valve body 20. The back face of front ferrule 42 defines a camming mouth 50 in which is received nose 52 of back ferrule 44. The back face 54 of back ferrule 44 is engaged by thrust surface 56 of coupling nut 58.

In making up the tube couplings 32, the ferrules 42, 44 are initially positioned as shown in FIG. 1 with the coupling nut 58 advanced over the threads 60 of the valve body a distance sufficient to impose a finger tight load on the ferrules. Thereafter, tube 34 is inserted into the coupling nut and valve body a distance sufficient to permit the conical end 36 to be seated against sealing surface 38 in initial non-pressure contact. Upon initial torquing of coupling nut 58, a longitudinal thrust will be imparted to back ferrule 44 by means of the thrust surface 56. Back ferrule 44 will in turn exert a substantially axial thrust against the front ferrule 42. Front ferrule 42 consequently will be forced into engagement with camming mouth 48. As a consequence of further torquing of the coupling nut 58, nose 46 of front ferrule 44 will be progressively wedged or cammed inwardly into engagement with the exterior surface of tube 34.

With further torquing of coupling nut 58, the front ferrule 42 will continue to move forwardly and inwardly, but at a reduced rate as a result of the increased resistance imposed by the surface of tube 34 and camming mouth 48. As resistance to movement of front ferrule 42 continues to build up, and the rate of front ferrule movement slows, the stiffness of the relatively short nose 52 of back ferrule 44 will be gradually overcome, as a result of which a progressively inward wedging or camming of the nose 52 of back ferrule 44 into engagement with the surface of tube 34 will commence.

The action of the ferrules just described is sequential in nature providing for time coordinated gripping by the front and back ferrules during take-up. The deformation of the ferrules also induces preloading in the tube end forcing the conical end 36 into sealing engagement with sealing surface 38. Various parameters are taken into account in the design of the coupling of FIG. 1 so as to produce the degree of preloading necessary to effect a seal at the sealing surface 38 sufficient to withstand the maximum working pressure for which the fitting is rated.

For a more detailed description of the tube coupling 32 just outlined, reference is made to application Ser. No. 760,576 assigned to the Sno-Trik Company of Cleveland, Ohio.

VALVE BODY Attention will now be directed to the interior of valve body 20 where it will be seen from FIG. 1 that bore 28 is enlarged at counterbore 62 to receive a seal washer 64, a sealing member 66, and an alignment bushing 68. Projecting through the respective members 64, 66, 68 is the cylindrical body 70 of the valve needle 72.

Seal washer 64 is generally annular in shape having an outside diameter slightly less than the diameter of counterbore 62 and a circular passageway 74 which has a diameter slightly in excess of the outside diameter of cylindrical body 70 for a purpose to be described more fully hereafter.

Sealing member 66, which in the preferred embodiment of this invention is manufactured from glass-filled TEFLON, is generally annular in shape and like seal washer 64 has an outside diameter slightly less than the diameter of counterbore 62 with a circular passageway 76 slightly larger than the outside diameter of cylindrical body 70.

Alignment bushing 68 includes a forward portion 80 having an outside diameter slightly less than the diameter of counterbore 62 and a circular passageway 78 having a diameter slightly in excess of the outside diameter of cylindrical body 70. Alignment bushing 68 also includes a flange portion 82 defining a thrust surface 84 which lies in a plane generally transverse to the axis of bore 28. Flange portion 82 is connected to the forward portion 80 of the alignment bushing 68 by a generally frusto-conical surface 86. Surface 86 and a corresponding surface 88 of valve body 20 define a bleed chamber 90 for a purpose to be described more fully hereafter.

In the preferred embodiment of the apparatus of this invention, seal washer 64, alignment bushing 68, valve needle 72 and valve body 20 are fabricated from Type 316 stainless steel. Other metals may be selected by one ordinarily skilled in the art depending upon the particular environment in which the valve is to be placed in service.

A packing nut 92 is threadedly received within valve body 20 through interengaging threads 94 defined on the packing nut and the valve body 20. Packing nut 92 includes an external hex surface 96 which is adapted to be engaged by a tool or other suitable instrument for the purpose of rotating the packing nut. The lower extremity of packing nut 92, as shown in FIG. 1, defines a driving surface 98 which lies in a plane generally parallel to thrust surface 84 of alignment bushing 68.

Disposed within packing nut 92 is a liner sleeve 100. Liner sleeve 100 includes a bore defining Acme threads 102 and a counterbore 104. Liner sleeve 100 is generally cylindrical in shape and is adapted to be received within packing nut 92 with the upper portion of the sleeve as shown in FIG. I engaging a shoulder 106 of the packing nut.

In the preferred embodiment of this invention, liner sleeve 100 is fabricated from brass or other similar metal whereas the packing nut itself and the stern are fabricated from Type 316 stainless steel. This arrangement tends to reduce galling of the threaded connection between the stem and the packing nut under high pressure conditions.

The two-piece structure including the packing nut 92 and the liner sleeve I00 lends itself to ease in manufacturing in that the threads 102 may be more readily formed in the sleeve with the sleeve thereafter disposed within the packing nut. Within the spirit of this invention, however, should be considered a one-piece packing nut in which the threads 102 are defined directly on the packing nut.

The upper portion of the packing nut is provided with a passageway 108 through which the valve actuating stern 109 protrudes.

The upper end of the valve actuating stem 109 as shown in FIG. 1 receives a valve handle 110. A rigid connection between the valve handle and the stem is provided by means of set screw 1 12 received within a tapped hole 115 of the valve handle and seated against a flat 114 of the valve stem. Access to set screw 112 may be had through passageway 116 of the valve handle.

The outer ends of the valve handle are outwardly flared as at 1 18 such that colored indicia in the form of plastic covering 120 may be shrunk in place or otherwise positioned about the exterior surface of the valve handle in order to designate the type of fluid passing through the valve. With indicia covering means shrunk in place about the valve handle, the outwardly flared portion 118 renders more difficult the inadvertent removal of the covering from the handle.

Threads 122 are provided on the actuating stem 109 and are adapted to cooperate with threads I02 defined by the liner sleeve 100. In the preferred embodiment of this invention, threads 122, 102 are of the Acme thread design for the purpose of providing thrust resistance against upward movement of the valve stem as the valve is pressurized. For this same purpose, the stem is threaded over a substantial length to insure that forces imposed on the threads are distributed over a broad area. While Acme threads have been found to be quite beneficial in the preferred embodiment of this invention, other thread forms well known to those skilled in the art may be considered equally within the scope of this invention.

The inner end of actuating stem 109 as shown in FIGS. 1 and 3 is enlarged being defined by a generally cylindrical surface 124 interconnected to the shank portion 126 of the stem by means of a tapered shoulder 128. It will be observed in FIG. 1 that the diameter of cylindrical surface 124 slightly exceeds the root diameter of threads 102 such that as the actuating stem 109 is backed out of the packing nut 92, a stop means will be provided as shoulder 128 abuts shoulder 130 defined by liner sleeve 100.

As is shown more clearly in FIG. 3, the inner end of actuating stem 109 is bifurcated with legs 132, 134 being defined by a cylindrical bore 136 intersected by a generally rectangular, axially directed slot 138 extending from bore 136 to the inner end of the actuating stem.

Cylindrical bore 136 is generally transverse to the axis 137 of the actuating stem 109 and together with slot 138 defines a chamber 140 for reception of one end of the valve needle 72 as will be described below.

VALVE NEEDLE Valve needle 72 is defined by a cylindrical body 70, an enlarged generally spherical surface 144 at one end thereof and a tip 146 at the other end thereof.

As will be evident in FIGS. 1 and 3, the spherical surface 144 of the valve needle 72 does not define a full sphere but rather defines a partial sphere; the extent of the spherical surface being more than a hemisphere but less than a full sphere. Within the spirit of this invention should be considered spherical surfaces of greater or lesser extent.

The diameter D (FIG. 3) of spherical surface 144 is approximately equal to the diameter D of the cylindrical bore 136 provided in the actuating stem 109. The breadth B of slot 138 as shown in FIG. 3 slightly exceeds the diameter of cylindrical body 70 of the needle 72, but is smaller in magnitude than the diameter D of bore 136. Thus, with the spherical surface 144 disposed within cylindrical bore 136 and cylindrical body 70 disposed within slot 138, a substantially line contact bearing zone will be established between the spherical surface 144 and the wall defining cylindrical bore 136. This line contact lies in the plane of either FIGS. 1 or 3.

It will be evident from FIGS. 1 and 3 that with the valve needle 72 disposed within the bifurcated end of actuating stern 109, the actuating stern will be otherwise free to rotate with respect to the valve needle. The line contact established between the spherical surface 144 and the wall defining cylindrical bore 136 permits a closing force to be imparted by the rotating actuating stem to the valve needle while at the same time maintaining friction at a minimum value thus to permit ready relative rotation of the valve needle and the actuating stem. Accordingly, the valve needle of this invention is nonrotating, i.e., rotary advancement of the actuating stem into the packing nut will produce a linear advancement of the valve needle into the valve seat without rotation of the valve needle relative to the sealing seat at the moment the needle and the slot contact one another.

The fit between the cylindrical body 70 of needle 72 and the members 64, 66, 68 is a sliding fit with a tolerance of about 0.0005 inches established between these members in the preferred embodiment. The cylindrical body 70 of the valve needle is thus guided and aligned with respect to the axis of the valve seat 30 such that tip 146 of the valve needle will be brought into precise engagement with the valve seat 30. Stated another way, the axis of the valve needle 72 and the axis of the valve seat 30 are very nearly coincident as the valve needle is guided by the respective members 64, 66 and 68.

It has been found that through the establishment of essentially line contact between the valve needle and the actuating stem that a substantial thrust force may be imparted to the valve needle by the valve stem without undue galling of the mating parts. In order to reduce still further the friction between the needle and the stem the spherical surface of the needle and the wall defining the stem bore may be coated with a suitable lubricant such as molybdenum.

As an optional feature, the preferred embodiment of this invention as shown in FIG. 1 is provided with a retaining ring 148 which is received in a peripheral recess 150 about the cylindrical surface 124 of the actuating stem. When in place as shown in FIG. 1, the retaining ring 148 serves to prevent outward expansion of the legs 132, 134 of the actuating stem, when the valve is under the influence of extremely high pressure. Retaining ring 148 thus insures that contact between the valve needle and the actuating stem will be along a line of substantial length. Obviously, any outward flaring of the legs 132, 134 would tend to reduce the length of the contact line between the actuating stem and the valve needle, with a resultant concentration of force over a smaller bearing zone. Such a contingency would tend to increase friction and galling with consequent impairment of valve function.

SEALING Sealing member 66 serves to prevent leakage of fluid through counterbore 62. Upon application of a compressive force to thrust surface 84 of alignment bushing 68 by packing nut 92, sealing member 66 expands slightly into sealing engagement with the wall defining counterbore 62 and with the external surface of cylindrical body 70 of the valve needle 72, thus sealing ofi the upper portion of the valve assembly from contact with fluids passing through the valve. Such compressive force is applied to the sealing member 66 as by threadedly advancing the packing nut 92 into the valve body by means of a suitable wrench or other implement.

When the desired degree of compression of the sealing member 66 has been achieved, a keeper 22 as shown in FIGS. 1 and 2 is fixed in place with the twelve point surface 152 of the keeper engaging the hex surface 96 of the packing nut. The keeper 22 thus prohibits rotation of the packing nut 92 in a manner so as to relieve the compressive force applied to scaling member 66. A relieving of the compressive force on the sealing member will obviously promote leakage of fluid through the threads of the packing nut and the actuating stem. Even more seriously, excessive packing nut rotation could weaken the connection between the packing nut and body to such an extent that the stem assembly and the nut would be forcibly ejected under the influence of the pressure in the system.

In the event of leakage past the sealing member 66 along the wall of counterbore 62, a bleed chamber 90 and bleed hole 166 provide a passage for high pressure fluid venting to atmosphere thus to avoid exertion of undue thrust force against the various valve components. In the event of leakage past the exterior surface of needle 72, transverse slots 93 provided in the end of packing nut 92 and sleeve 100 establish communication between counterbore 104, passageway 78 and bleed hole 166.

NEEDLE TIP The tip of the valve needle may take different forms within the spirit of this invention. The valve needle 72 of FIG. 1 includes a shut-off tip 146 which is defined by a conical surface 154 (FIG. 3) adapted to be brought into sealing engagement with the valve seat 30.

Other forms of tips for the valve needle may be employed within the spirit of this invention and several such forms are shown in FIGS. 6-8.

In FIG. 6, a valve needle is shown including a shut-off and control tip. The frusto-conical surface 156 of FIG. 6 provides a shut-off of the valve whereas the plug surface 158 is adapted to cooperate with the valve seat 30 in order to restrict flow through the valve in a controlled manner.

The valve needle of FIG. 7 is provided with a metering tip in the form of a relatively long frusto-conical surface 160. The valve metering tip of FIG. 7 is adapted to cooperate with the valve seat in order to provide varying flow of fluid through the valve depending upon the degree of insertion of the metering tip into the valve seat.

The valve needle of FIG. 8 is provided with a soft seat tip comprised of a frusto-conical surface 162 and a soft seating element 164.

All of the valve needles of FIGS. 6-8 have similar spherical surfaces 144 and cylindrical bodies 70. These valve needles are thus compatible with the actuating stem 109 of FIG. 1 and, depending upon the needle desired, may be readily inserted into the bifurcated end of the valve stem.

DESCRIPTION OF THE METHOD This invention is also directed to a method of assembly of a needle type valve. With reference to FIGS. 1 and 4, the method steps ofthis invention are:

1. providing a valve body 20 having inlet and outlet passageways 24, 26 and a valve seat 30 disposed therebetween;

2. providing a valve actuating stem 109 having a bifurcated inner end defined by a cylindrical bore 136 with an axially directed slot 138 extending from the bore to the inner end of the actuating stem, the slot having a breadth somewhat smaller in magnitude than the diameter of said bore;

3. providing a valve needle 72 having a tip 146 at one end thereof and a spherical enlarged surface 144 at the other end thereof;

4. disposing the valve needle and the stem in side-by-side relationship (as shown in FIG. 4) with the center of the spherical surface of the needle disposed along the axis of the cylindrical bore in the stem;

5. advancing the spherical surface of the valve needle into the cylindrical bore of the stem; and

6. attaching the valve stem in the valve body.

Within the spirit of this invention should also be considered the method steps of disposing an annular ring 148 about the bifurcated inner end of the actuating stem after advancing the needle into the stem as well as the method step of plating or otherwise depositing on the spherical surface of the needle and/or on the wall defining the cylindrical bore of the stem, with a lubricant prior to the mating of the respective parts.

ADVANTAGES OF THE INVENTION This invention provides an apparatus and method suitable for high pressure valve service. I

The valve includes a needle that may be readily replaced in the event of damage to the needle or in those instances where it is desired to replace the needle with one of an alternate design.

The construction of a valve body and the cooperating needle including alignment and sealing elements provides a valve that is designed to handle difficult applications involving extreme pressure and where resistance to hazardous or corrosive fluids is required.

The alignment bushing 68 and cooperating seal washer 64 provide for accurate alignment of the valve needle with respect to the valve seat. The alignment bushing and seal washer further cooperate with the sealing member 66 to prohibit the leakage of fluid into the stern thread area of the valve where contamination of the fluid may take place. In addition, the alignment bushing and seal washer provide support for the valve needle which eliminates chatter of the needle under the influence of high pressure with the valve opened.

The cooperating ball of the valve needle and the cylindrical bore of the stem permit a substantial thrust force to be imparted to the needle by the stem without undue galling of the mating parts.

In the event that it is desired to replace the needle, the method of this invention provides for ready removal of the needle with replacement by an identical needle or a needle of an alternate design. There is thus great flexibility in the method and the operator can readily choose the valve function to suit his particular requirements by simply installing an appropriate needle using the method.

The rugged valve design provides for trouble free service over an extended period of time. The valve of this invention has been rated by the manufacturer at 60,000 p.s.i. working pressure. This is a conservative rating of the capabilities of the valve.

The invention claimed is:

1. A valve comprising:

a valve body having a valve seat disposed between inlet and outlet passageways;

a valve actuating stem, said stem having a bifurcated inner end defined by a transverse bore extending through said stem and an axially directed slot extending from said bore to the inner end of said stem, said slot having a breadth somewhat smaller in magnitude than that of said bore;

a valve needle having a cylindrical body, a generally spherical enlarged surface at one end thereof, and a tip at the other end thereof adapted to cooperate with said seat;

said one end of said valve needle adapted to be received in said bifurcated end of said stem with said spherical surface in contact with the wall defining said bore;

said bore being generally cylindrical, and in which the contact between said bore and the enlarged spherical surface of said needle is substantially on a line;

alignment and sealing means for said valve needle;

a rigid seal washer having a bore slightly larger than the diameter of said needle body and providing a sliding fit for said needle body;

a sealing member adjacent said seal washer;

a stem alignment bushing adjacent said sealing member,

said bushing having a bore slightly larger than the diameter of said needle body providing a sliding fit for said needle body;

a packing nut threadedly received in said valve body and adapted to contact said bushing and apply a compressive force to said sealing member; and

a threaded liner sleeve provided in said packing nut and said valve stem being threadedly received in said liner.

9 l 2. The invention of claim 1 and further including a retaining 5. The invention of claim 1 in which said other end of said ring disposed about said bifurcated end whereby said end is valve dl i d fi d b a fl eat ti restrained asainst spreadins apart and said valve needle is n 6. The invention of claim 1 in which said other end of said tured with said spherical surface disposed within said bore. valve needle is defined by a shubofiup.

3. The invention of claim 1 in which said valve stem is pro- 7. The invention of claim 2 in which said other end of said vided with Acme threads.

4. The invention of claim 1 in which said other end of said valve needle is defined by a tapered metering tip.

valve needle is defined by a shut-off and control tip.

It I. 1 I l 

1. A valve comprising: a valve body haVing a valve seat disposed between inlet and outlet passageways; a valve actuating stem, said stem having a bifurcated inner end defined by a transverse bore extending through said stem and an axially directed slot extending from said bore to the inner end of said stem, said slot having a breadth somewhat smaller in magnitude than that of said bore; a valve needle having a cylindrical body, a generally spherical enlarged surface at one end thereof, and a tip at the other end thereof adapted to cooperate with said seat; said one end of said valve needle adapted to be received in said bifurcated end of said stem with said spherical surface in contact with the wall defining said bore; said bore being generally cylindrical, and in which the contact between said bore and the enlarged spherical surface of said needle is substantially on a line; alignment and sealing means for said valve needle; a rigid seal washer having a bore slightly larger than the diameter of said needle body and providing a sliding fit for said needle body; a sealing member adjacent said seal washer; a stem alignment bushing adjacent said sealing member, said bushing having a bore slightly larger than the diameter of said needle body providing a sliding fit for said needle body; a packing nut threadedly received in said valve body and adapted to contact said bushing and apply a compressive force to said sealing member; and a threaded liner sleeve provided in said packing nut and said valve stem being threadedly received in said liner.
 2. The invention of claim 1 and further including a retaining ring disposed about said bifurcated end whereby said end is restrained against spreading apart and said valve needle is captured with said spherical surface disposed within said bore.
 3. The invention of claim 1 in which said valve stem is provided with Acme threads.
 4. The invention of claim 1 in which said other end of said valve needle is defined by a tapered metering tip.
 5. The invention of claim 1 in which said other end of said valve needle is defined by a soft seat tip.
 6. The invention of claim 1 in which said other end of said valve needle is defined by a shut-off tip.
 7. The invention of claim 2 in which said other end of said valve needle is defined by a shut-off and control tip. 